As an advanced service with all features of 3G communication service, the mobile video telephone service enters into reality more and more nearly with the coming of 3G service. The mobile video telephone is a point-to-point communication service by using video and voice at the same time, and it accomplishes a two-way real-time exchange of video and voice between the mobile terminal and mobile terminal, immobile video telephone terminal or PC and so on. The mobile video telephone combines mobile communication technology and television technology and is provided with functions of watching, listening and talking; it uses the International Telecommunication Union (ITU-324) standard, integrates videography, picture, voice compressed, MPEG coding and decoding in a whole and is a technology with well development foreground.
In prior art, if a user initiates a video telephone calling to a called user by using a mobile terminal, while the mobile terminal of the called user doesn't have the function of video telephone communication or the network of the called party can't support the function of video telephone so the video telephone can't be received, both sides have to withdraw to the voice communication. The specific way of withdrawing has been prescribed in relevant international standards. However, if the mobile terminal of the called party is a video telephone user, and when the calling mobile terminal user dials the called mobile terminal but the called user is inconvenient or unwilling to answer the video telephone, the present network system can't deal with it. Accordingly, there is not any relevant provision in the existing international standard and the relevant technical solution has not been found in this field.